Nanotechnology could improve satellites and solar cells

Scientists at the NanoPower Research Labs at Rochester Institute of Technology, led by director Ryne Raffaelle, are using nanotechnology to explore this possibility through a project funded by an $847,109 grant from the U.S. Department of Defense. The project aims to take current state-of-the-art solar cells used for space power to the next level by developing nanostructured materials and, ultimately, by producing nanostructured cells. The program may extend to three and half years, with total funding reaching $3 million.

"If successful, the results of this program will improve current solar array and satellite technology, and lay the foundation for long-term improvement in our ability to use solar energy," Raffaelle says.

Unique to this project is the ability to exploit the fundamental behavior of nanoscale crystals, also known as quantum dots, which alter the way a solar cell absorbs light and converts it into electricity. According to Raffaelle, the electrical, optical, mechanical and even thermal properties of nanomaterials can be controlled by changing the particle size, making them highly useful in semiconductor device development.

Today’s current solar-cell technology used for space power relies upon three individual photovoltaic junctions used in a series. These so-called triple-junction solar cells—consisting of the chemical compounds, germanium, gallium arsenide and indium gallium phosphide—are grown latticed-matched on top of one another. Raffaelle’s team will augment the middle cell in the three-layered sandwich with a quantum dot array to enhance its short-circuit current and improve the overall efficiency of the triple junction cell.

"The use of the quantum confinement offered by nanostructured materials provides us with a new means of breaking out of the normal design constraints associated with ordinary crystalline device growth,” says Raffaelle. “The theoretical improvements that this can provide are truly remarkable. It’s our job to turn these theories into experimental realities."

Raffaelle’s nanotechnology research illustrates the possibilities of the newly opened IT Collaboratory on the RIT campus.

"When Governor Pataki announced the creation of the IT Collaboratory at RIT, he did so with the understanding that the center would participate in the creation of a stronger, more vibrant economy as a result of its technological innovations,” says Russell Bessette, M.D., executive director of NYSTAR. “This DOD award will help further cement RIT’s role as an engine for economic growth and opportunity in the Finger Lakes region as well as statewide."